U.S. Pat. No. 4,195,732 (Bell), which is assigned to the assignee of this application, discloses a highly successful roll support and spacing member. The structure disclosed in the Bell patent is formed from an elongated bar of expanded foam material such as polystyrene. The structure is used for palletizing rolls of web material, such as film or the like, and cushions the rolls to protect against damage in handling and shipment. The elongated bars include a plurality of spaced, semi-cylindrical roll indentations along at least one of their surfaces to receive the rolls of web material. In order to effectively protect the rolls of web material, the semi-cylindrical indentations provide a relatively snug fit against the respective roll. The relatively snug fit prevents severely uneven load distribution which can flatten rolls. In some circumstances, flattened rolls are unusable to the end user. In addition, relatively even load distribution over the indentation is important to eliminate denting or scratching of the roll. Scratches on rolls often cause zippering when the roll is run on a web machine, thus rendering the roll completely unusable. The elongated bars of expanded foam also include a plurality of recesses located within or adjacent the side portions of the semi-cylindrical roll indentations to provide flexural cushioning. The flexural cushioning recesses in the semi-cylindrical roll indentations provide for the requisite balance between strength and flexibility, and prevent the foam bars from cracking in use. In such construction, the bars are permitted to conform to different diameter rolls without causing breakage to the bars or load collapse. The bars of the Bell patent permit limited relative movement among the rolls of the stack while, at the same time, are of sufficient strength to prevent crushing and collapse of the stack.
In use, the elongated bars of the Bell patent may be placed between the bottom layer of rolls and the supporting pallet, between subsequent layers of rolls in the stack, and on top of the top layer of the stack. In one form of stacking arrangement, each layer contains a number of rolls of web material arranged in parallel and axial orientation. The supporting bars may be arranged parallel to one another and spaced apart with the end portions of each roll supported on a semi-cylindrical roll indentation provided on adjacent spaced bars. For example, a semi-cylindrical roll indentation provided by an interiorly located bar normally supports the end portions of two rolls of web material. Also, the Bell patent discloses one embodiment which provides an integral lip along one of the outside edges of the semi-cylindrical roll indentation to protect an otherwise exposed axial end of a roll from nicks or other damage.
Although the expanded foam roll support and spacing members as disclosed in the Bell patent have been highly successful, many companies (including the assignee of this application) have more recently also begun to manufacture somewhat similar roll support and spacing members made from molded pulp. It is important that such molded pulp roll support and spacing members have sufficient strength to prevent crushing and collapse of the stack, and also have sufficient flexibility to permit limited relative movement among the rolls of the stack. Heretofore, molded pulp roll support and spacing members have also normally included recesses in the semi-cylindrical roll indentations. The recesses are important to provide the molded pulp roll support and spacing members with the delicate balance between strength and flexibility necessary for adequate cushioning of the rolls.
Recesses in the semi-cylindrical roll indentations of molded pulp roll support and spacing members have been deemed critical for several reasons. First, the recesses strengthen the dried molded pulp member to prevent crushing of the member under heavy loads. If crushing occurs, stacks can loosen. Also, load distribution on the rolls of web material is compromised, and the rolls of web material can flatten. In addition, the presence of recesses in the semi-cylindrical indentations maintains the strength of the cushioning roll indentations for the rolls even when the diameter of the rolls is reasonably inconsistent (e.g. 1 to 2 inch variance in roll diameter among rolls). Secondly, the recesses help to maintain the shape and dimension of the semi-cylindrical roll indentations during the fabrication process. As mentioned, it is important for performance that the shape and dimensions of the semi-cylindrical roll indentations be maintained within suitable tolerances. The recesses help in this regard by supporting the wet molded pulp member during the drying process to prevent sagging or other similar distortions.
Recesses and/or ridges in the semi-cylindrical roll indentations, however, often mark, dent or scratch the roll (e.g. nicks, creases, etc.) especially under heavy loads.